The present invention relates generally to containers, and more particularly, to a container, which is easily contracted to reduce its capacity and elastically expanded to restore its original capacity.
Generally, containers may contain something which is not transformed in shape or reduced in quantity regardless of consumption, but usually contain something which is reduced in volume as it is consumed. In the case of containing liquid food in the container, as a user drinks the liquid, the food in the container is decreased in quantity and empty space in the container becomes larger. Due to such an increased empty space, the container is inefficient in terms of its space utilization. In addition, since the container with the increased empty space undesirably maintains its original volume, it is inconvenient for a user to carry the container.
In order to solve the above problem, as shown in FIG. 4, a collapsible container has been proposed and widely used to contain liquid material. A plurality of annular folding lines are formed around the circumferential surface of the container at regular intervals. The folding lines are designed to allow the collapsible container to be expanded or contracted at the folding lines in a zigzag mode so as to appropriately control the capacity of the container. That is, when a large quantity of material is required to be contained in the container, a user pulls up on the container for increasing its capacity. On the other hand, when the quantity of contents is decreased, the user presses down on the container for reducing its capacity.
Such a collapsible container is advantageous in that its capacity can be controlled. However, this container has a problem that it doesn""t have a restoring force in itself for restoring its original shape, so a user has to manually pull up on or press down on the container when necessary, thus being complicated to control the capacity of the container. Furthermore, the conventional collapsible container has another problem that it is inferior in terms of hygiene, since dirt may be caught in the channels, formed inside the container along the folding lines, during containing something in the container, and the dirt can hardly be removed from the container due to the bellows shape of the collapsible container.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a container, which is easily expanded or contracted and ensures the easy removal of dirt.
In order to accomplish the above object, an embodiment of the present invention provides a container, including a flexible body having a cylindrical interior for containing something, and a capacity control ring spirally formed around the outer surface or inner surface of the sidewall of the body, and allowing the body to be contracted and expanded in a vertical direction thereof, thus controlling the capacity of the body.
It is preferable that the capacity control ring have a hollow passage interiorly formed along the ring, and a coil spring received in the hollow passage and providing an elasticity to the body for allowing the contraction and expansion of the body. It is also preferable that the capacity control ring be a solid ring.
It is further preferable that a spiral collapsible groove be formed on the sidewall of the body along a spiral channel formed between turns of the capacity control ring.
It is still further preferable to have a lid closing the mouth of the body and having an air valve for allowing air to be discharged from the interior of the body.
In order to accomplish the above object, another embodiment of this present invention provides a container, including a flexible body having a cylindrical interior for containing something, a seat groove spirally formed around the sidewall of the body, a coil spring set along the seat groove and providing an elasticity to the body for allowing elastic contraction and expansion of the body, a collapsible groove spirally formed around the sidewall of the body along a spiral land formed between turns of the seat grove for allowing the body to be easily contracted and expanded, and a lid closing the mouth of the body and having an air valve for allowing air to be discharged from the interior of the body.